The present invention is directed to a brake control unit, and more specifically to an improved brake control unit for providing a brake output signal to a brake load of a towed vehicle.
Various prior art brake control units have included a display to provide an operator of a towing vehicle with various information. These displays have included a plurality of light emitting diodes (LEDs) and/or one or more seven-segment displays. The LED type display has typically provided an indication of the magnitude of the output (i e., a brake output signal) of the brake control unit and the seven-segment type display has generally provided a numerical value for the brake output signal. While some prior art brake control units have provided status and diagnostic information, the status and diagnostic information has been somewhat limited. For example, information provided through a plurality of LEDs has required an operator of the towing vehicle to decode the meaning of the LEDs to determine what information the brake control unit was attempting to provide to the operator.
Some prior art brake control units have also included a processor for receiving a brake control signal from an accelerometer. The brake control signal provided by the accelerometer has been utilized to determine when the towing vehicle was decelerating so that a brake output signal (e.g., an energizing current) could be applied to a brake load (i.e., brake electromagnets) of a towed vehicle (e.g., a trailer), in response to the deceleration of the towing vehicle. These prior art brake control units have typically required an operator of the towing vehicle to set or adjust, by mechanical means, a reference level of the accelerometer; when the brake control unit was initially mounted or changed to a different mounting orientation. These accelerometers typically only functioned over a small range and required leveling to be on the edge of detection. In general, prior art brake control units have not accounted for changes in the accelerometer output (i.e., the brake control signal) due to temperature variation. In addition, prior art brake control units have only provided a brake output signal to a brake load of the towed vehicle when the towing vehicle was moving in a forward direction. As such, the brakes of the towing vehicle have been required to hold the towed vehicle when the towing vehicle was stopped on an incline and to stop the towed vehicle when the towing vehicle was backing-up.
What is needed is a brake control unit that eliminates the need to manually adjust the level of the accelerometer when the brake control unit is initially mounted or changed to a different mounting orientation. Additionally, it would be desirable for the brake control unit to automatically adjust for the changes in the accelerometer output that are due to temperature variations. Further, it would be desirable for the brake control unit to display a wide range of status and diagnostic information to an operator of the towing vehicle. In addition, it would be desirable for the brake control unit to provide a proportional brake output signal to a brake load of a towed vehicle when stopping in reverse and a fixed brake output signal when the towing vehicle is stopped with the brake pedal depressed. Furthermore, it would also be desirable for the brake control unit to be capable of automatically setting a gain level and/or boost level for the brake control unit.
An embodiment of the present invention is directed to a brake control unit for providing a brake output signal to a brake load of a towed vehicle and includes a processor, an accelerometer and a memory subsystem. The accelerometer is coupled to the processor and provides a brake control signal to the processor. The processor is programmed to cause an appropriate brake output signal to be provided to the brake load responsive to the brake control signal. The memory subsystem is coupled to the processor and stores processor executable code which causes the processor to automatically set at least one of a gain level and a boost level for the brake control unit.
According to another embodiment of the present invention, brake control code causes the processor to perform a number of steps. First, the processor causes a brake output signal to be provided to the brake load of the towed vehicle when a brake pedal of a towing vehicle is depressed and before brakes of the towing vehicle can respond to the depression of the brake pedal. Next, the processor detects a deceleration in the towed vehicle attributable to the brake output signal. The detected deceleration provides an indication of towed vehicle characteristics. Finally, the processor sets the gain level for the brake control unit responsive to the detected deceleration associated with the brake output signal.
In yet another embodiment of the present invention, the brake control code causes the processor to perform the additional step of setting the boost level for the brake control unit responsive to the detected deceleration associated with the brake output signal. The boost level causes an increased initial braking force to be applied to the brake load, when utilized. The towed vehicle characteristics may include items such as brake temperature, brake pad wear, proximity of brake pads to brake drum, brake magnet strength, brake spring strength, number of axles, load and speed and the detected deceleration may also provide an indication of road conditions.
According to yet another embodiment of the present invention, the brake output signal is modulated at a given rate to provide an average deceleration for use in setting the gain level for the brake control unit to an appropriate level.
These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.